US3753425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two stroke internal combustion engines
Assignee: Individual
•
Filing: 1971-09-14
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Granted: 1973-08-21
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Expires: 1991-09-14
Abstract
Abstract The specification discloses a two-stroke engine employing crankcase compression wherein a charge of lubricant and fuel passes through a first transfer passage in a stationary part of the engine. The transfer passages for the or each cylinder communicate at one only of the journals of the crankshaft and the second transfer passage is branched and leads to inlet parts located so as to give loop scavenging of the cylinder. The rotary axis of the crankshaft may be vertical and said journal the upper journal which is thus well lubricated since at least the majority of the cylinder charge is exposed to the journal bearing.
Inventors
- 👤 B Hooper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:30
CPC Classifications
F; F01; F01M; F01M3/00; F02; F02B; F02B25/00; F02B75/00; F02B75/02; F02B2075/022; F02B2075/025; F02B2700/00; F02B2700/03; F02B2700/037; F02B61/00; F02B61/04; F02B61/045; F02B75/007
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
187 words
A two-stroke engine comprising: a stationary part including a crankcase and a cylinder block, a cylinder arranged horizontally in the cylinder block and a crank chamber in the crankcase; means to supply a fuel and lubricant mixture to said crank chamber; inlet and exhaust port means in the cylinder wall; a crankshaft rotatably mounted with its rotary axis vertical in the crankcase and having upper and lower journals received respectively in upper and lower journal bearings in the crankcase; a piston slidable in the cylinder between top and bottom dead centre positions; a connecting rod connecting the piston to the crankshaft; first and second transfer passage means associated with the cylinder, the first transfer passage means being formed in the crankshaft and extending between the crank chamber and a location adjacent to said upper journal bearing only and the second transfer passage means comprising a branched passage extending from said location to the inlet port means for providing, in conjunction with the exhaust port means, loop scavenging of the cylinder; and means to lead lubricant from the lower surface of the crankchamber to the lower journal bearing.
Claim 2
Dependent Claim
187 words
A two-stroke engine comprising: a stationary part including a crankcase and a cylinder block, a cylinder arranged horizontally in the cylinder block and a crank chamber in the crankcase; means to supply a fuel and lubricant mixture to said crank chamber; inlet and exhaust port means in the cylinder wall; a crankshaft rotatably mounted with its rotary axis vertical in the crankcase and having upper and lower journals received respectively in upper and lower journal bearings in the crankcase; a piston slidable in the cylinder between top and bottom dead centre positions; a connecting rod connecting the piston to the crankshaft; first and second transfer passage means associated with the cylinder, the first transfer passage means being formed in the crankshaft and extending between the crank chamber and a location adjacent to said upper journal bearing only and the second transfer passage means comprising a branched passage extending from said location to the inlet port means for providing, in conjunction with the exhaust port means, loop scavenging of the cylinder; and means to lead lubricant from the lower surface of the crankchamber to the lower journal bearing.
Claim 3
Dependent Claim
18 words
An engine according to claim 1 wherein said location is adjacent to and above said upper crankshaft journal.
Claim 4
Dependent Claim
14 words
An engine according to claim 1 wherein the exhaust port means is directed downwardly.
Claim 5
Dependent Claim
268 words
A two-stroke engine comprising: a stationary part including a crankcase and a cylinder block, at least two cylinders arranged horizontally in the cylinder block, one above the other, and a number of separate crank chambers in the crankcase, the number of such chambers being equal to the number of cylinders and each chamber being associated with a different cylinder; means to supply a fuel and lubricant mixture to said crank chambers; iNlet and exhaust port means in the wall of each cylinder; a crankshaft rotatably mounted with its rotary axis vertical in the crankcase and having an upper journal bearing adjacent its upper end, a lower journal bearing adjacent its lower end and a number of intermediate journal bearings equal in number to one less than the number of cylinders, each intermediate journnal bearing interposed between two adjacent crank chambers; a piston slidable in each cylinder between top and bottom dead centre positions; a connecting rod connecting each piston to the crankshaft; separate first and second transfer passage means associated with each cylinder, each first passage means being formed in the crankshaft and extending only between the crank chamber associated with the cylinder and a location adjacent to the journal bearing adjacent the upper end of said crank chamber, and each second transfer passage means comprising a branched passage extending from said location to the inlet port means of the associated cylinder for providing, in conjunction with the exhaust port means of the cylinder, loop scavenging of the latter; and means to lead lubricant from the lower surface of the lowermost crank chamber to the lower journal bearing.
Claim 6
Dependent Claim
268 words
A two-stroke engine comprising: a stationary part including a crankcase and a cylinder block, at least two cylinders arranged horizontally in the cylinder block, one above the other, and a number of separate crank chambers in the crankcase, the number of such chambers being equal to the number of cylinders and each chamber being associated with a different cylinder; means to supply a fuel and lubricant mixture to said crank chambers; iNlet and exhaust port means in the wall of each cylinder; a crankshaft rotatably mounted with its rotary axis vertical in the crankcase and having an upper journal bearing adjacent its upper end, a lower journal bearing adjacent its lower end and a number of intermediate journal bearings equal in number to one less than the number of cylinders, each intermediate journnal bearing interposed between two adjacent crank chambers; a piston slidable in each cylinder between top and bottom dead centre positions; a connecting rod connecting each piston to the crankshaft; separate first and second transfer passage means associated with each cylinder, each first passage means being formed in the crankshaft and extending only between the crank chamber associated with the cylinder and a location adjacent to the journal bearing adjacent the upper end of said crank chamber, and each second transfer passage means comprising a branched passage extending from said location to the inlet port means of the associated cylinder for providing, in conjunction with the exhaust port means of the cylinder, loop scavenging of the latter; and means to lead lubricant from the lower surface of the lowermost crank chamber to the lower journal bearing.
Claim 7
Dependent Claim
26 words
An engine according to claim 4 wherein each said location is adjacent to and above the journal bearing adjacent the upper end of said crank chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |